Incandescent lamp socket

ABSTRACT

1302774 Lampholders GTE SYLVANIA Inc 14 July 1970 [14 July 1969] 34193/70 Heading H2E A lampholder 14 for accommodating a lamp 12 with prong-type terminals and a lamp locking and ejecting arrangement comprises a lever 32 pivotally mounted with spaced locking tabs 40 and ejecting tabs 42 disposed above and below a ledge 75 (Fig. 2) on the lamp. A spring 56 operates on the lever in that locked position (Fig. 1) to hold the locking tabs against the top of ledge 75. Downwards movement of the protruding lever 32 disengages the locking tabs and engages the ejecting tabs with the ledge 75 thereby ejecting the lamp (Fig. 2), until the hooks 58 engage the ears 44, then the spring no longer applies torque to the lever 32. To insert a lamp the lever must be in the lampejected position initially. The centre portion of the torsion spring 56 is anchored by a pivot (50, Fig. 3, not shown) secured to side compartment 30. The body of the lamp holder 14 is made of a refractory material and mounted on the interconnecting yoke section (16, Fig. 3, not shown) with an insulation pad (70) positioned therebetween. The lamp holder is retained in position by bolts passing through the slots (26, Fig. 4, not shown) in the mounting tabs (24, Fig. 4, not shown).

Sept. 1, 1970 w. R. MATTSON ET AL 3,526,868

INGANDESCENT LAMP SOCKET Filed July 14, 1969 WILLIAM R. MATTSON RICHARD J.-SHEA INVENTORS BY TTORNEY United States Patent 3,526,868 INCANDESCENT LAMP SOCKET William R. Mattson, West Gloucester, and Richard J. Shea, Danvers, Mass., assignors to Sylvania Electric Products Inc., a corporation of Delaware Filed July 14, 1969, Ser. No. 841,499 Int. Cl. H01r 13/ 62 US. Cl. 33945 3 Claims ABSTRACT OF THE DISCLOSURE A socket adapted to retain a projection-type lamp in an optically fixed position within a visual projection system. The lamp is locked in place by a spring actuated lever that is thrown into this position by insertion of the lamp into the socket. This same spring actuated lever can be manipulated to eject the lamp.

FIELD OF THE INVENTION In portable visual aid applications, such as overhead projectors, the lamp used for illumination must be securely fixed to the socket. This locked-in lamp arrangement has a two-fold purpose, mainly it is so that the apparatus can be transported from one site to another without removing the lamp. The other reason is that the lamp is usually operated other than in a base down position, therefore, it must be secured in place. The socket of this invention not only firmly holds the lamp in an optically aligned position, but can be used to eject the lamp by manipulation of a single, spring-actuated lever.

PRIOR ART Various means for locking the lamp to the socket have previously been used in projection systems. Some were designed as bendable tabs or screw-type mounts that provided the necessary locking. However, they made lamp replacement time consuming and inconvenient. In these cases, a hot lamp had to be handled or time was spent waiting for the lamp to cool.

SUMMARY OF THE INVENTION According to our invention, we have designed a unique lamp socket which overcomes the above mentioned disadvantages. In our lamp socket, an actuator lever controlled by a torsion spring is utilized to lock the lamp in the socket as well as to eject it when replacement is required. To insert a lamp the electrical contacts are initially fitted into the socket and the lower edge of the base is disposed between a set of lock tabs on the actuator lever. The actuator lever is then tripped. This action forces the lever into a locked position and the tabs on the lever engage a ledge on the lamp base. The torsion spring is designed so that a locking force occurs during insertion and an open position occurs when the actuator lever is tripped to eject the lamp.

When ejecting the lamp from the socket, the actuator lever is moved counter to insertion. A set of ejecting tabs on the actuator lever are disposed beneath the lamp base and movement of the actuator lever will lift the lamp out of the socket. When this movement is completed, it places the actuator lever in an open position. The lever can stay in this position until a new lamp is inserted into the socket between the locking tabs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the socket and a lamp locked in position.

FIG. 2 is a view similar to FIG. 1 but with the lamp in an ejected position.

3,526,868 Patented Sept. 1, 1970 FIG. 3 is a side elevational view of the socket and lamp. FIG. 4 is a top view of the socket only.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, the socket 10 of our invention is shown having a lamp 12 illustrated in phantom line, locked in its operative position. In FIG. 2, the same lamp 12 is shown being ejected from the socket 10.

The basic socket 10 has a generally rectangular main body 14 made from a refractory insulating material. A metal bracket or yoke 16 having four upstanding arms 18 encompasses the body 14 and retains it through pivot studs 20, 21 positioned at either end. These studs extend through holes provided in the upstanding legs 18 and rest in concave grooves (not shown in the drawing) which prevent lateral movement. The lower end of bracket 16 is provided with mounting tabs 24, each of which has an elongated slot 26 for the adaption of screws or bolts, when the socket is secured to an apparatus.

In addition to preventing lateral movement of the body 14, studs 20 and 21 form supports for the ejection mechanism. Stud 20 supports spring-retaining bail 30 and stud 21 supports an actuator lever bail 32. As viewed in FIGS. 1 and 2 the actuator lever bail 32 pivots on approximately one third its length on stud 21. The longer portion of the lever is provided with a lateral web area 36 which connects an identically shaped lever on the opposite side of the body 14 and is pivotally supported on the other end by stud 21. Each short portion of the lever 32 is provided with two inwardly directed tabs 40 and 42 and a spring retaining ear 44. The function of tabs 40 and 42 will be described hereinafter in the description of the operational sequence.

As mentioned previously, the spring retaining bail 30 is pivoted at both ends on pivot 20. The inside surface of the web portion of the bail is provided with a stud 50 (as seen in FIG. 3) and a torsion spring 52 is anchored thereabout. The torsion spring 52 is directed beneath the legs of bail 30, each end of which extend toward the lever 32. The end portions of the spring 52 are shaped as angled cam surfaces 56 with terminating hook ends 58. The cam surfaces 56 of spring 52 liein grooves disposed on the retaining ears 44 of lever 32 and the hook ends 58 provide a limiting means for the lever 32.

As viewed in FIG. 2 when the cam lever 32 is in its opened operative position, the spring is in a dormant spring position, that is, it is retained in the crook of the terminating end. In comparison to FIG. 1, the lever 32 is in its locked position when the spring 32 having its inclined cam surface 56 bearing against the cars 44 which provides spring tension to lever 32.

As viewed in FIGS. 1 and 4 electrical connectors for the lamp are located in the main insulated body 14 and provide the necessary electrical connection to operate a lamp. In FIG. 4, two receiving holes 64 are shown in the main body one slightly larger than the other which insures proper alignment of the lamp 12. The e ectrical connectors are not shown but are standard cup connectors fixed to the end of lead-in wires 68. The connectors are aliged with the holes 64 and provide proper electrical connection to the prongs of the lamp 12. As viewed in FIG. 3, an insulator pad 70 is positioned between the bracket 16 and the connectors providing a complete insulated receiver.

Insertion and ejection of the lamp from the socket can be described with reference to FIGS. 1 and 2. In FIG. 2, a view of the socket is shown where a lamp 12 is in position to be placed into the socket 10. As mentioned above,

the lever 32 in this position does not have the tension that normally is provided by the spring 52. As the prongs of the lamp are slipped into the mating holes 64 of the socket, the lower end of a ledge 75 on the lamp base contacts the inwardly directed ejecting tabs 42 of lever 32. Forcing the prongs, and hence the base into socket will rotate the lever 32 to a point where locking the tabs 44 will ride down the cam portion of the spring 52. At a point approximately midway of the length of the angle portion the spring will overcome the resistance of the lever thereby snapping it into a locked position shown in FIG. 1. Locking tabs 40 then come to rest over the ledge 75. The lever is tensioned in this position by the spring 52 laying against locking tabs 44.

Ejection of the lamp is accomplished by reversing the procedure. Pressure applied to the end of the lever 32 which brings the ejecting tabs 42, now lying at the bottom of clearance space in the body, to a point underneath the base of the ledge 75. Further movement of the lever will fully eject the lamp.

As our invention we claim:

1. A lamp holder comprising: socket means adapted to hold a prong type lamp, lever means pivotally associated with said socket means, locking tabs and ejecting tabs separated from each other disposed on said lever means and adapted to be disposed above and below a ledge on the lamp; spring means bearing against said lever means and adapted to hold the locking tabs against the top of the ledge in a locked position and to abut the bottom of the ledge during ejection, said socket means including a flat metal bracket having a first set and a second set of oppositely disposed upstanding legs at each end thereof and an insulated lamp receiving body portion fitted and held within the confines of the legs; a pair of pivot studs fitted to each top end of the legs to retain saidlamp receiver with the bracket.

2. The holder according to claim 1 wherein said lever means includes indentical side members joined and spaced from one another by a flat web portion, said side members connected to said pivot studs on the first set of upstanding legs of said metal bracket and said side members each having an outwardly directed spring retaining tab.

3. The holder according to claim 2 wherein said spring MARVIN A. CHAMPION, Primary Examiner T. P. LEWIS, Assistant Examiner US. Cl. X.R. 

